Landfill mining: resource potential of Austrian landfills – evaluation and quality assessment of recovered municipal solid waste by chemical analyses

Since the need for raw materials in countries undergoing industrialisation (like China) is rising, the availability of metal and fossil fuel energy resources (like ores or coal) has changed in recent years. Landfill sites can contain considerable amounts of recyclables and energy-recoverable materials, therefore, landfill mining is an option for exploiting dumped secondary raw materials, saving primary sources. For the purposes of this article, two sanitary landfill sites have been chosen for obtaining actual data to determine the resource potential of Austrian landfills. To evaluate how pretreating waste before disposal affects the resource potential of landfills, the first landfill site has been selected because it has received untreated waste, whereas mechanically–biologically treated waste was dumped in the second. The scope of this investigation comprised: (1) waste characterisation by sorting analyses of recovered waste; and (2) chemical analyses of specific waste fractions for quality assessment regarding potential energy recovery by using it as solid recovered fuels. The content of eight heavy metals and the net calorific values were determined for the chemical characterisation tests. </jats:p

Landfill mining: development of a theoretical method for a preliminary estimate of the raw material potential of landfill sites

In recent years, the rising need for raw materials by emerging economies (e.g. China) has led to a change in the availability of certain primary raw materials, such as ores or coal. The accompanying rising demand for secondary raw materials as possible substitutes for primary resources, the soaring prices and the global lack of specific (e.g. metallic) raw materials pique the interest of science and economy to consider landfills as possible secondary sources of raw materials. These sites often contain substantial amounts of materials that can be potentially utilised materially or energetically. To investigate the raw material potential of a landfill, boreholes and excavations, as well as subsequent hand sorting have proven quite successful. These procedures, however, are expensive and time consuming as they frequently require extensive construction measures on the landfill body or waste mass. For this reason, this article introduces a newly developed, affordable, theoretical method for the estimation of landfill contents. The article summarises the individual calculation steps of the method and demonstrates this using the example of a selected Austrian sanitary landfill. To assess the practicality and plausibility, the mathematically determined raw material potential is compared with the actual results from experimental studies of excavated waste from the same landfill (actual raw material potential)

sj-docx-1-wmr-10.1177_0734242X241231408 – Supplemental material for Consumers confused ‘Where to dispose biodegradable plastics?’: A study of three waste streams

Supplemental material, sj-docx-1-wmr-10.1177_0734242X241231408 for Consumers confused ‘Where to dispose biodegradable plastics?’: A study of three waste streams by Namrata Mhaddolkar, Alexia Tischberger-Aldrian, Thomas Fruergaard Astrup and Daniel Vollprecht in Waste Management & Research</p

Enzymatic Recycling of High-Value Phosphor Flame-Retardant Pigment and Glucose from Rayon Fibers

Viscose (also known as Rayon) filaments are obtained from regenerated cellulose and are used in many different sectors mainly as reinforcement material in tires and other cord applications and in the clothing industry. The incorporation of a phosphor-containing pigment imparts flame-retardancy properties to these fibers, which then can be used as part of personal protection textiles delivering wear comfort. There are no recycling strategies for these materials being brought to landfills or chemically degraded since incineration is difficult because of their flame retardancy. In this study, an enzyme-based strategy for the recovery of glucose and of the phosphor pigment without altering their chemical structures was developed as a circular economy solution. Rayon fibers were completely hydrolyzed by a cellulase preparation while 98% of the glucose (reducing sugar assay and HPLC analysis) and more than 99% of the flame-retardant pigment present in the fibers was recovered. The recovered pigment was analyzed via ¹H, ¹³C, and ³¹P NMR, and the purity >95% was comparable to that of the commercially available pigment. The recovered glucose was successfully used as carbon source for ethanol production by <i>Saccharomyces cerevisiae</i> while the recycled phosphor pigment was reused in viscose filament production leading to similar mechanical properties like those measured for virgin fibers. This work presents an environmentally friendly recycling strategy of functional rayon fibers for the recovery of the two major components, namely, glucose and the pigment